There are many applications for the use of high tensile strength bolts, such as in bridgework, steel building structures and the aircraft industry, to name a few. In such structures, the maintenance of proper bolt tension is most important. Obviously, if bolt tension is insufficient or below requirements in any way, the joint secured by the bolt will be substandard in the strength that is desired. Also, if a bolt is over stressed, there is always a possibility of failure in the joint of the fastener assembly.
In many applications using high tensile strength bolts in fastener assemblies, it is important to maintain a desired bolt tension throughout the life of the fastener assembly. Thus, it is desirable to frequently or periodically monitor the tension of the fastener assembly.
One form of monitoring bolt tension is set out in U.S. Pat. No. 4,773,272, Trungold, issued Sep. 27, 1988 as well in a corresponding Canadian Patent 1,311,944 of Dec. 29, 1992.
The present invention sets forth improvements in the art such as the Trungold disclosures.